Ventricular–Vascular Stiffening in Patients With Repaired Coarctation of Aorta

Is the medical treatment for arterial hypertension after primary aortic coarctation repair related to age at surgery? A retrospective cohort study

BACKGROUND

Hypertension following primary coarctation repair affects up to a third of subjects. A number of studies suggest that future hypertension risk is reduced if primary repair is performed at a younger age.

OBJECTIVES

The objective of this study was to evaluate the risk of future medical treatment for hypertension depending on age of primary coarctation repair.

METHODS

This study was carried out at a tertiary paediatric cardiology referral centre. Retrospective database evaluation of children aged 28 days and ⩽12 months), and children (>12 months). Main outcome measure is the need for long-term anti-hypertensive medication. The risk for re-coarctation was also evaluated.

RESULTS

A total of 87 patients were analysed: 60 neonates, 17 infants, 10 children. Among them, 6.7% neonates, 29.4% infants, and 40% children required long-term anti-hypertensive medications. Group differences were statistically significant (p=0.004). After adjustment for type of repair, the risk of long-term anti-hypertensive therapy was 4.5 (95% confidence interval 1.2-16.9, p=0.025) and 10.5 times (95% confidence interval 2.6-42.3, p=0.001) higher if primary repair was carried out in infancy and childhood, respectively, compared with neonates. Among all, 13 patients developed re-coarctation: 21.7% in the neonatal group, 5.9% in the infant group, and 20% in the child group. We could not demonstrate a significant difference between these proportions or calculate a reliable risk for developing re-coarctation.

CONCLUSIONS

Risk of medical treatment for hypertension was lowest when primary repair was carried out during the neonatal period, rising 10-fold if first operated on as a child. Knowing the likelihood of hypertension development depending on age of primary repair is useful for long-term surveillance and counselling.

Changes in echocardiographic parameters and hypertensive disorders in pregnancies of women with aortic coarctation

OBJECTIVES

Pregnancy can be well tolerated after the repair of aortic coarctation. However, a higher incidence of hypertensive disorders during these pregnancies was reported. We analyzed the perinatal changes in echocardiographic parameters in women with aortic coarctation and investigated the risk factors of gestational hypertension (GH).

METHODS

We retrospectively identified 15 pregnancies in nine Japanese women with aortic coarctation between 1982 and 2015. We categorized the patients according to the presence/absence of GH as the group with GH(n=3) and that without GH(n=12). The echocardiographic parameters were compared between groups.

RESULTS

Our analysis revealed that a pre-pregnancy Doppler-measured pressure gradient≥20mmHg and a left ventricular mass index≥95g/m² were significant risk factors for GH. The left ventricular end-diastolic diameters at the first and the third trimesters, the left ventricular end-systolic diameters at the first trimester, and the left ventricular ejection fraction at the third trimester were also significantly higher in the pregnancies with GH. All of these findings had been obtained before the patients' GH occurred.

CONCLUSIONS

Hypertrophy of the left ventricle with a lower ejection fraction and a high pressure gradient across the coarctation were risk factors for GH in the patients with aortic coarctation. Thus, serial measurements using echocardiography are important for predicting GH in women with aortic coarctation. However, further research investigating this finding with a larger sample size is needed.

Impact of Transcatheter Intervention on Myocardial Deformation in Patients with Coarctation of the Aorta

Myocardial deformation measured by speckle tracking echocardiography can detect subtle abnormalities of left ventricular function before an obvious abnormality in traditional echocardiographic parameters such as ejection fraction is seen. We hypothesized that patients with coarctation of the aorta (CoA) may have impaired myocardial deformation that may persist even after successful transcatheter intervention. This is a retrospective study to assess the myocardial deformation in patients undergoing transcatheter intervention of CoA. The data were compared with age-matched normal controls. Echocardiographic parameters were obtained before, immediately and at median 6 months (range 3-8 months) after transcatheter intervention. Myocardial deformation indices were obtained off-line using Tomtec 2D Cardiac Performance Analysis Software. Repeated measure ANOVA was used to compare the indices between three time points. Independent sample t test or Chi-square test was used to compare data between groups. Twenty-four patients (age 13.5 ± 7.7 years) underwent successful transcatheter CoA intervention (stent 19, balloon angioplasty five) improving CoA peak gradient in the catheterization laboratory from 27.1 ± 11.3 to 4.5 ± 3.0 mmHg (p < 0.001). To compare with normal controls (n = 25, age 14.5 ± 1.9 years), fraction shortening was significantly higher in pre-intervention CoA patients (40.4 ± 7.1 vs. 33.8 ± 2.4 %, p < 0.001). In contrast, CoA patients had significantly abnormal left ventricular longitudinal strain compared to normal controls (-14.9 ± 2.6 vs. -20.5 ± 1.8 %, p < 0.001). In CoA patients, left ventricular longitudinal strain improved immediately and 3-8 months after intervention (-18.0 ± 2.9 and -17.6 ± 2.9 %, p < 0.007) but continued to be abnormal compared to normal controls. Patients with CoA had impaired myocardial deformation compared to normal controls. Myocardial mechanics improved but did not normalize even after successful transcatheter intervention on CoA in the short term.

The Medium-Term Effects of Treatment for Mild Aortic Recoarctation

Objective:

To assess medium-term effects of treatment for mild to moderate recoarctation in an adult population.

Design:

We identified all patients who had coarctation repair between 1965 and 1985 in our institution. They were all (n = 156) invited to a thorough outpatient examination, which was accepted by 133. Eleven (median age 36 [28-53] years) were identified with isolated mild to moderate recoarctation and received reintervention. They comprise the patient population of the current study. We performed bicycle exercise testing, transthoracic echocardiography, magnetic resonance imaging, and 24-hour blood pressure monitoring before and 14 to 29 months after reintervention.

Results:

Compared to the values before reintervention, 24-hour blood pressures were reduced, but only significantly so for nighttime values. On echocardiography, wall thickness was reduced (1.2 ± 0.3 vs 1.1 ± 0.2, P > .05), and maximum flow velocity in the distal aortic arch decreased (2.8 ± 0.5 m/s vs 2.1 ± 0.4 m/s, P < .05). The invasive coarctation gradient was significantly reduced (15 ± 7 mm Hg vs 5 ± 9 mm Hg, P < .05), and the diameter at the coarctation site was increased (11 ± 3 mm vs 15 ± 3 mm, P < .05). Maximum achieved workload increased (182 ± 51 W vs 205 ± 65 W, P < .05). Cardiac symptoms were overall reduced.

Conclusion:

Reintervention was overall beneficial in increasing exercise capacity and reducing symptoms in the medium term, but the effects on established myocardial hypertrophy and blood pressures were less profound. Larger studies are needed in order to establish the definite role of reintervention for patients with milder recoarctation.

Noninvasive Assessment of Vascular Function in Postoperative Cardiovascular Disease (Coarctation of the Aorta, Tetralogy of Fallot, and Transposition of the Great Arteries)

Using noninvasive techniques, we sought to assess arterial stiffness, impedance, hydraulic power, and efficiency in children with postoperative tetralogy of Fallot (TOF), coarctation of the aorta (COA), and transposition of the great arteries (TGAs). Results were compared with those of healthy peers. Fifty-five children with repaired congenital heart disease (24 TOFs, 20 COAs, and 11 TGAs) were compared with 55 age-matched control subjects (CTRL). Echocardiographic Doppler imaging and carotid artery applanation tonometry were preformed to measure aortic flow, dimensions, and calculate pulse wave velocity, vascular impedance and arterial stiffness indexes, hydraulic power (mean and total), and hydraulic efficiency (HE) which were calculated using standard fluid dynamics equations. All congenital heart disease subgroups had higher pulse wave velocity than CTRL. Only the COA group had higher characteristic impedance. Mean power was higher in TGA than in CTRL and TOF, and total power was higher in TGA than in CTRL and TOF. Hydraulic efficiency was higher in TOF than in COA and TGA. In conclusion, children with TOF, COA, and TGA have stiffer aortas than CTRL. These changes may be related to intrinsic aortic abnormalities, altered integrity of the aorta due to surgical repair, and/or acquired postsurgery. These patients may be at increased long-term cardiovascular risk, and long-term follow-up is important for monitoring and assessment of efforts to reduce risk.

Exercise-induced cardiopulmonary arrest in a child with aortic stenosis

The beneficial effect of exercise restriction in preventing sudden cardiac death in children with aortic stenosis remains unclear. We report the case of a 15-year-old boy with congenital aortic stenosis who was resuscitated after sudden cardiac arrest during exercise. The case led to the new concept that exercise restriction may prevent not only unpredictable ventricular ischaemic events and associated arrhythmias but also progressive ventricular hypertrophy.

Percutaneous treatment of adult isthmic aortic coarctation: acute and long-term clinical and imaging outcome with a self-expandable uncovered nitinol stent

BACKGROUND

To present perioperative and long-term results of percutaneous treatment of adult isthmic coarctation of the aorta by means of a self-expandable closed-web uncovered nitinol stent (Sinus-XL, Optimed, Esslingen, Germany).

METHODS AND RESULTS

Preoperative, perioperative, and long-term clinical and computed tomographic angiography data were collected and analyzed prospectively. A total of 52 consecutive patients were treated with the Sinus-XL stent. Mean age was 36.6 (21-67) years, peak invasive trans-coarctation of the aorta gradient was 54.7 ± 9.9 mm Hg, and upper body hypertension unresponsive to medical treatment was present in all patients. Mean stent diameter and length were 24.2 mm (22-28 mm) and 70.4 mm (40-80 mm), respectively. Eight patients (15.4%) required coarctation of the aorta predilatation. All patients underwent poststent dilatation with a noncompliant balloon. Postoperative peak gradient (3.3 ± 2.5 mm Hg) was reduced significantly (P < 0.001) and minimal aortic diameter was increased significantly (4.6 ± 1.9 versus 18.6 ± 2.5 mm; P < 0.001). All patients were discharged home (mean hospitalization, 3.5 days). At follow-up (47.6 months; 12-84), 1 (1.9%) noncardiovascular mortality was reported. Aortic computed tomography confirmed the absence of stent collapse and secondary migration and documented stability in aortic diameter (18.3 ± 2.7 mm). Thirty patients (57.7%) were completely weaned-off antihypertensive medications and their use dropped from 2.6 to 0.9 drugs/patient (P < 0.001). Ankle-brachial pressure index increased from 0.75 to 0.98 (P < 0.001).

CONCLUSIONS

Adult coarctation of the aorta treatment by means of a self-expandable uncovered stent is safe and durable. The peculiar stent design maintains adequate localized radial strength over time with minimal trauma on the adjacent aortic wall and negligible device-related complications. Blood pressure control optimization is immediate and persistent even at long-term follow-up.

Late hypertension in patients with repaired aortic coarctation

Coarctation of the aorta represents more than a simple obstructive lesion, as there is often evidence of hypertension and vascular dysfunction despite successful surgery at an early age. There are ample data showing that a large proportion of patients develop arterial hypertension, and this appears to increase with age. Our understanding of the pathogenesis of late hypertension is incomplete, and there is limited information on which drugs are most appropriate. Increased arterial rigidity is now well described in this patient group, although it is not known how this should influence therapy. The increase in afterload associated with this increased rigidity has been found to have an impact on the left ventricle at an early stage, and the interaction between the vascular dysfunction and the ventricle is an area of interest and active research. This article reviews some recent studies and highlights areas where research questions remain.

Coarctation of the aorta associated with Dandy-Walker variant

This article reports a rare case of coarctation of the aorta associated with Dandy-Walker variant in a 17-year-old girl. Differential diagnoses of coarctation of the aorta and Dandy-Walker variant are extensively discussed. In addition, standard surgical treatment of coarctation as well as new approaches such as endovascular stenting are described in detail to provide therapeutic insights into her management. Although surgical or endovascular repair of coarctation results in significant improvement of systemic hypertension and is associated with better survival, cardiovascular complications are still very common. Thus, long-term follow-up after repair is required, and high-quality imaging studies such as echocardiography, CT and MRI are warranted.

Advances in interventional and hybrid therapy in neonatal congenital heart disease

In addition to the considerable surgical advances in treating congenital heart diseases, hybrid and transcatheter therapies have become a cornerstone of neonatal cardiology within the last decade. Approaches to the care of cyanotic newborns with congenital heart disease focused on manipulations of the inter-atrial septum, right ventricular outflow tract obstructions, and on the arterial duct as the source for pulmonary blood flow. Currently, fewer interventional procedures are used in newborns and small infants to treat excessive pulmonary blood flow caused by shunt lesions, but transcatheter techniques and hybrid strategies have been developed to treat newborns suffering from inadequate systemic perfusion. However, transcatheter techniques are still not available to treat failing systemic ventricles without obvious structural disorders of the myocardium or dilated cardiomyopathies in newborns and infancy, despite new surgical-interventional strategies are already developed to avoid or to delay early heart transplantation. In conclusion, material and technical improvements have enabled transcatheter techniques to replace medical-based therapies to solve structurally dependent cardiovascular diseases. However, evidence-based and long-term follow-up data are required.

Fluid dynamics of coarctation of the aorta and effect of bicuspid aortic valve

Up to 80% of patients with coarctation of the aorta (COA) have a bicuspid aortic valve (BAV). Patients with COA and BAV have elevated risks of aortic complications despite successful surgical repair. The development of such complications involves the interplay between the mechanical forces applied on the artery and the biological processes occurring at the cellular level. The focus of this study is on hemodynamic modifications induced in the aorta in the presence of a COA and a BAV. For this purpose, numerical investigations and magnetic resonance imaging measurements were conducted with different configurations: (1) normal: normal aorta and normal aortic valve; (2) isolated COA: aorta with COA (75% reduction by area) and normal aortic valve; (3) complex COA: aorta with the same severity of COA (75% reduction by area) and BAV. The results show that the coexistence of COA and BAV significantly alters blood flow in the aorta with a significant increase in the maximal velocity, secondary flow, pressure loss, time-averaged wall shear stress and oscillatory shear index downstream of the COA. These findings can contribute to a better understanding of why patients with complex COA have adverse outcome even following a successful surgery.

Systemic blood pressure after stent management for arch coarctation implications for clinical care

OBJECTIVES

The goal of this study was to prospectively assess blood pressure (BP) and echocardiographic parameters to delineate the incidence and nature of the hypertension burden in this cohort.

BACKGROUND

Few data are available on the long-term outcomes of aortic stenting.

METHODS

Thirty-one patients with successfully stented coarctation during childhood (mean age 12.4 years) underwent 24-h ambulatory BP monitoring (ABPM), exercise BP measurement, and echocardiographic assessment.

RESULTS

Mean time after stent implantation was 5.3 ± 4 years. Hypertension was noted on one-off right-arm BP assessment in 3 patients (10%), but on the basis of the 24-h ABPM assessment in 14 patients (45%). Twenty-four of 31 patients (80%) had an abnormally elevated exercise BP response. Peak exercise BP correlated with left ventricular mass index (r = 0.51; p < 0.05), which was also significantly increased in the entire cohort (mean = 91.3 g/m(2); p < 0.05). In patients with significant somatic growth since implantation, the indexed diameter of the stent (to aortic diameter) had significantly decreased from the 48th percentile at the implantation to the 4th percentile during the study (p < 0.05). There was no difference in any parameter between patients with native or those with recurrent coarctation.

CONCLUSIONS

Hypertension is endemic in patients with stented coarctation, irrespective of the absence of residual obstruction. Due to abnormal BP homeostasis, hypertension should be aggressively pursued by ABPM assessment and exercise stress testing in this population. Relative hypoplasia of the stented arch after somatic growth may contribute to this tendency and should provoke consideration of elective serial redilation of coarctation stents.

Correlation of exercise response in repaired coarctation of the aorta to left ventricular mass and geometry

The role of exercise testing to risk stratify patients with repaired coarctation of the aorta (CoA) is controversial. Concentric left ventricular (LV) hypertrophy, defined as an increase in the LV mass-to-volume ratio (MVR), is associated with a greater incidence of adverse cardiovascular events. The objective of the present study was to determine whether a hypertensive response to exercise (HRE) is associated with increased LVMVR in patients with repaired CoA. Adults with repaired CoA who had a symptom-limited exercise test and cardiac magnetic resonance imaging examination within 2 years were identified. A hypertensive response to exercise was defined as a peak systolic blood pressure >220 mm Hg during a symptom-limited exercise test. The LV mass and volume were measured using cardiac magnetic resonance by an investigator who was unaware of patient status. We included 47 patients (median age 27.3 years, interquartile range 19.8 to 37.3), who had undergone CoA repair at a median age of 4.6 years (interquartile range 0.4 to 15.7). Those with (n = 11) and without (n = 36) HRE did not differ in age, age at repair, body surface area, arm-to-leg systolic blood pressure gradient, gender, or peak oxygen uptake with exercise. Those with a HRE had a greater mean systolic blood pressure at rest (146 ± 18 vs 137 ± 18 mm Hg, p = 0.04) and greater median LVMVR (0.85, interquartile range 0.7 to 1, vs 0.66, interquartile range 0.6 to 0.7; p = 0.04) than those without HRE. Adjusting for systolic blood pressure at rest, age, age at repair, and gender, the relation between HRE and LVMVR remained significant (p = 0.001). In conclusion, HRE was associated with increased LVMVR, even after adjusting for multiple covariates.

Elderly hypertensives: how are they different?

Once considered an inconsequential part of the aging process, the development of isolated systolic hypertension represents a late manifestation of increased elastic artery stiffness and is the predominant hypertensive subtype in the middle-aged and elderly populations. Its inherent increased risk for vascular events, such as coronary heart disease, stroke, heart failure, peripheral artery disease, chronic kidney disease, and dementia, highlights the importance of its control. The purpose of this short review is to summarize how hypertension is different in the elderly when compared with "essential hypertension" in younger adults. The emphasis will be on the multiple ways that increased artery stiffness affects the natural history and clinical manifestations of hypertension in the elderly.

Isoproterenol stress test during catheterization of patients with coarctation of the aorta

BACKGROUND

The exercise test is considered useful in selecting high-risk patients with repaired coarctation of the aorta (CoA), but it is difficult to obtain the cooperation of pediatric patients. The present study determines the feasibility of the isoproterenol stress test (IST) among pediatric patients with CoA.

METHODS

Thirteen patients with repaired or mild preoperative CoA aged 1-207 (median 13) months underwent 16 IST during cardiac catheterization. Peak-to-peak pressure gradients (PG) over the coarctation site were measured at baseline and at IST. Balloon angioplasty (BAP) was applied to patients with significant stenosis on angiography.

RESULTS

The PG between the ascending and the descending aorta was significantly higher at IST than at baseline (20.5 ± 11.5 vs 5.6 ± 3.9 mmHg, P < 0.0001). Heart rate, the systolic blood pressure measured at the ascending aorta, and pulse pressure were all significantly higher at IST than at baseline. The PG at IST decreased >10 mmHg in three of six patients after BAP.

CONCLUSIONS

Significant pressure gradients over the coarctation site develop at IST in pediatric patients with repaired CoA or in preoperative patients with mild coarctation.

Aortic stiffness and aortic dilation in infants and children with tetralogy of Fallot before corrective surgery: evidence for intrinsically abnormal aortic mechanical property

OBJECTIVE

The present study tested the hypothesis that there is an intrinsic abnormality of aortic elasticity in infants/children with tetralogy of Fallot (TOF) before corrective surgery. The study also determined the independent and quantitative effects of aortic volume load on aortic dilation in this group of TOF patients.

METHODS

Aortic stiffness (pulse wave velocity; PWV) and aortic volume load (aortic volume flow) were measured during catheterization in 37 infants and children with TOF before corrective surgery and in 55 control subjects.

RESULTS

PWV was significantly higher in TOF patients than in controls, irrespective of age, sex, hemodynamic burden on the aortic wall, and existence of aorto-pulmonary shunt. Aortic diameter was also significantly greater in TOF patients than in controls. Multivariate regression analysis identified aortic volume load as an independent determinant of aortic dilation (aortic diameter = 0.72 aortic flow + 26.1 body surface area + 2.79, r(2) = 0.58, p < 0.001). Increased aortic-wall stiffness correlated with the increase in aortic diameter in patients with dominant left-to-right shunt (without aortic volume load); aortic diameter = 0.007 PWV + 13.5 body surface area (BSA) + 6.3 (r(2) = 0.73, p < 0.05).

CONCLUSIONS

The present study highlighted the intrinsic abnormality of the mechanical property of the aortic wall as a feature of aortopathy in TOF. The study also indicated that aortic volume overload and, to a lesser extent, intrinsically high aortic stiffness correlated significantly with aortic dilation in TOF.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: outflow tract obstruction, coarctation of the aorta, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part II of the guidelines includes recommendations for the care of patients with left ventricular outflow tract obstruction and bicuspid aortic valve disease, coarctation of the aorta, right ventricular outflow tract obstruction, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Left ventricular and ascending aortic function after stenting of native coarctation of aorta

Patients with surgically corrected aortic coarctation have increased proximal aortic stiffness that might contribute to the known worse cardiovascular outcomes. We examined the effect of stenting on the mid-term ascending aortic elastic properties and its relation to cardiac structure and function in adults with native coarctation of the aorta. A total of 20 consecutive patients (13 men, age at stenting 30 + or - 8 years) were prospectively studied before and 14 + or - 2 months after coarctation stenting. The aortic stiffness index was calculated using the ascending aortic diameters and right arm blood pressure values. The ventricular long-axis function was assessed using pulsed-wave tissue Doppler imaging at the septal site. The results were compared to those from 31 normal controls. Statistically significant improvement was found in aortic narrowing (catheter-derived gradient 32 + or - 11 vs 10 + or - 6 mm Hg), left ventricular mass index (132.8 + or - 50.1 vs 114.7 + or - 47.7 g/m(2)), long-axis function, and left atrial volume index (26.5 + or - 5.3 vs 23.7 + or - 5.6 mm(3)/m(2)). The patients continued to have a thicker left ventricle, reduced long-axis function, and larger left atrium after intervention than did the controls. They also had impaired proximal aortic function with respect to the controls that remained unchanged after stenting (aortic stiffness index 10.7 + or - 4.5 to 10.1 + or - 3.0). The poststenting aortic stiffness index correlated modestly with the left ventricular mass index and reduced long-axis velocity. In conclusion, aortic stenting resulted in partial mid-term improvement in cardiac structure and function in adults with coarctation of aorta but the ascending aortic elastic properties remained abnormal. Such a degree of impairment was related to residual left ventricular hypertrophy and dysfunction. Early identification of such patients and optimum management might avoid these irreversible ventriculoaortic disturbances and their known consequences.

Coarctation of the aorta: evaluation and management

PURPOSE OF REVIEW

Coarctation of the aorta is the discrete narrowing of the proximal descending aorta and is the sixth most common lesion in congenital heart disease. Repair of the coarctation can relieve the obstruction, but recurrent coarctation and future aneurysm formation can occur, and a heightened risk of vascular disease is present. This review focuses on advances in the management of native and previously treated coarctation and provides insights into future vascular risk.

RECENT FINDINGS

Coarctation of the aorta is associated with other left heart obstructive lesions, and advances in the genetic basis of these conditions have been made. Recurrent coarctation and aneurysm formation are common after surgical and endovascular repair of coarctation of the aorta. Endovascular treatment is an acceptable alternative to surgical repair of native and recurrent coarctation. Covered stents and stent grafts can be used to treat arch complications with a low risk of complications. In spite of repair of the obstruction, hypertension persists and appears to be multifactorial due to a variety of factors, including endothelial dysfunction, aortic stiffness, altered arch morphology and increased ventricular stiffness.

SUMMARY

People with previously repaired coarctation of the aorta require long-term surveillance for local complications with aortic imaging and surveillance and management of hypertension to prevent vascular disease.